The present invention relates to a steering controlling apparatus for trailers transporting freight. Recently, large trailers have been developed, but the recently developed large trailers still have disadvantages in case of running on the narrow or very curved roads, and trains (freight trains) must run on rails only which requires unloading to trucks or trailers for the purpose of transporting freight to other locations.
The present invention is to provide a steering controlling apparatus for trailers which makes trailers able to run like a freight train even in town or on narrow roads by means of making all the wheels of the trailers connected by the steering controlling apparatus of the invention capable of running on the wheel trace of the tractor, such as with a train.